<template>
    <h1>父组件</h1>
    <h1>{{ num  }}</h1>
    <hr>
    <sub-com v-model="num"></sub-com>
</template>
<!-- 在script标签上 写入setup 就是 setup入口函数的语法糖  -->
<script setup>
import SubCom from './components/Sub4.vue'
import {ref} from 'vue'
let  num = ref(0)
</script>
<script>
export default {
name: 'App',
}
</script>
